Process of extracting uranium and vanadium from ores.



UNITED STATES PATENT oF i-on HERMAN. ELEOK AND WILLIAM GEORGE HA'LDANE, OF GOLDEN AND EDWIN LYMAN WHITE, OFDENVER, COLORADO.

PROCESS OF EXTRACTING URANIUM AND VANADIUM FROM ORES.

Specification of Letters Patent.

Patented June 9, 1908.

Original application filed June 18, 1907, Serial No. 379,658. Divided and. this application filed September 30, 1907.

Serial No. 395,310.

To all whom it may concern:

Be it known that we, HERMAN FLnoK and WILLIAM. G. HALDANE, residing at Golden, Jefferson county, Colorado, and EDWIN L. WHITE, residing at Denver, Denver county, Colorado, have invented certain new an useful Improvements in Processes of Extracting Uranium and Vanadium from Ores, of which the following is a specification.

The object of. this invention is to prov de a method of. extracting uranium, vanadium and other values from ores containin same while fully utilizing the acid so vent employed the method is applicable to a yariety of'ores containing uranium or vanadium, but will be described by reference to the treatment of carnotite, or ores containing carnotite as a constituent 'mineral. This ;mineral often occurs as an impregnation or incrustation in the sand stones or shales of western Colorado and-Utah, usually yellow or light brown in color but sometimes colored blue or green by carbonates of copper.

We may proceed-substantially as follows; The ore is crushed, preferably to 20-44) mesh, by any suitable means, and is then agitated with hot sulfuric acid of 15-20 percent. concentration, the proportion of acid 'used depending'u on the quality of the ore;

as a rule four hun red pounds of sulfuric acid of 65, Baum, diluted to 152() percent.

will'be found sufficient for the treatment of one ton of ore. The resulting acid solution contains the uranium, vanadium and copper values, and is preferably filtered or otherwise clarified. The resulting clear acid solution is then brought into contact with fresh ore,

being preferably heated and agitated in contact therewith, whereby the solution is neutralized; at the same time a part of the uranium, vanadium and other values, frequently accompanied by iron, is precipitatedupon the ores as basic sulfates or carbonates, effect of this precipitation being to enrich the ore which may be initially of a low grade. The neutral solution isagain clarified if necessary and constitutes a portion of. the stock solution suitable for further treatment ror the separation of the values as hereinafter described. The enriched ore which has served for the neutralization of the'acid solution, either alone or mixed with fresh'ore, is treated with sulfuric acid as above described, yielding an acid solution which after neutralithe " ing quantity of the zation as above is added to the stock solution. The ore residues from the treatment: with sulfuric acid, as Well as the residues fromthe similar treatment of the enriched ore,-are' freed from remaining values by washing with dilute sulfuric acid or acidulated water; the

resulting acid washings are then'strengthened by the addition of sulfuric acid to a preferred concentration of 15-20 percent, and are utilized for the continuance of the process. j The substantially neutral stock solution containing uranium, vanadium and usually copper and iron' is then treated with sulfurous acid,'usually by subjectin the solu tion to thefaction of sulfur dioxidby roasting sulfur effects the reduction of the iron and'vanadium compounds present to the ferrous and vanadous states res ectively, a correspondsul ur ,dioxid being simultaneously oxidized to sulfur. triox'id and combining with the water of the solution to form sulfuric acid. In thus reducing the iron to the ferrous condition the advantage is secured that in the subsequent precipitation of the uranium and vanadium les 's iron is precipitated-and the valuesare therefore obtained in more concentrated form. A further important advantage is that the sulfuric acid derived from the sulfur dioxid is available for the treatment of additional quantities of ore, and may be utilized by adding to the acid solution a (iuantity of ore just sufficient to neutralize t e same while avoiding the precipitation of any values; the

residue from the ore employed for neutralization is utilized in the initial state of the process.

The reduced and substantially neutral pounds of iron, and hydrated calcium sulfate,

utilized, and precipitates uranium basic sulfor the direct extraction of the, values withmethod as a whole is both economical and eilicient.

This application is a division of a rior application filed June 18th, 1907, Seria I No. 379,658.

0 claim:

1. The method of uranium which consists-in subjecting the ore to a solution of su'lfurous acid to extract uranium and heatin the resulting solution, thereby expelling sulfur dioxid and precipi tating uranium as basic suliite.

1s initially green but changes rapidly in air to light green or yellow. It may be profitably shipped, r preferably after drying, "or drying and igniting to effect a further concentration of the values. Or the values may be further refined or concentrated by any known orsuitable method. For instance they may be treated wet or dry with sulfurous acid solution, which takes 11 the values forming a greenish solution of su fites this solution when boiled evolves sulfur dioxid, which may be recovered and again fite, which may be ignited to uranium oxid. The vanadium remains in solution and may be preci itated, together with some iron, by caustic ime,

Sulfurous acidto a solution of sulfurous acid to extract uranium, heating the resulting solution to expel sulfur dioxid and precipitate uranium may be used on some ores as basic sulfite, igniting the precipitate, and

recovering sulfur dioxid. out previous treatment with sulfuric acid; this may be accomplished by passing sulfur dioxid into water covering the ore, the entire niassbeing heated and agitated, preferably under )ressure. The values pass into solution wiich is drawn off and if necessary filter-pressed or otherwise clarified. Upon boiling the clear liquor, sulfur dioxid is re covered, and the uranium is precipitated as basic sulfite and subsequently ignited to uranium oxid. The vanadium remains in solution and may be recovered by precipitation by caustic lime as above described.-

'It will be observed that the method as above described involves the complete utilization of the sulfuric acid employed as a solvent, as well as of the acid formed in solution with the concurrent reduction ofthe compounds of'iron and vanadium, and that uranium and vanadium which consists in acid to extract uranium and vanadium, heating the resulting solution to expel sulfur dioxid and precipitate uranium as basic sulfite, and precipitating vanadium from the residual solution by caustic lime,

4. The method of treating ores containing uranium or vanadium which consists in subjectin'g the ore to a solution of sulfurous acid under pressure to extract the values, and recovering the values from the resulting solution. v

In testimony whereof we have fixed our signatures in the presence of two witnesses.

HER-MAN FI'ECK. WILLIAM GEORGE HALDANE. EDWIN LYMAN WHITE.

it istherefore very economical as regards' Witnesses: consumption of told The precipitation.- JAS. MoKILLoP, and refining of the values are accomplished VIRGINIA-PADEN.

by the use of inexpensive reagents, and thetreating ores containing 2; The method of treating ores containing urannnn wlnch consists in sub ectmgthe ore ,3. The method of treating ores containing subjecting the ore to a solution of sulfurous, 

